diff options
Diffstat (limited to 'Demo/parser/unparse.py')
| -rwxr-xr-x[-rw-r--r--] | Demo/parser/unparse.py | 33 |
1 files changed, 29 insertions, 4 deletions
diff --git a/Demo/parser/unparse.py b/Demo/parser/unparse.py index e1c2719..3fac1c0 100644..100755 --- a/Demo/parser/unparse.py +++ b/Demo/parser/unparse.py @@ -1,3 +1,4 @@ +#! /usr/bin/env python3.1 "Usage: unparse.py <path to source file>" import sys import math @@ -311,11 +312,35 @@ class Unparser: self.write(t.id) def _Num(self, t): - if isinstance(t.n, float) and math.isinf(t.n): - # Subsitute overflowing decimal literal for AST infinity - self.write("1e" + repr(sys.float_info.max_10_exp + 1)) + # Python doesn't have negative numeric literals, but in Python + # 2.x and early versions of Python 3.1, there's a compile-time + # operation that turns "-<number>" into a single _Num, instead + # of an unary minus applied to a _Num. Here we reverse that. + infstr = "1e" + repr(sys.float_info.max_10_exp + 1) + + if isinstance(t.n, complex): + # check that real part is as expected: 0 with appropriate sign + print(t.n) + print(str(t.n.real), str(math.copysign(0.0, t.n.imag))) + assert str(t.n.real) == str(math.copysign(0.0, t.n.imag)) + negate = math.copysign(1.0, t.n.imag) < 0 + elif isinstance(t.n, float): + negate = math.copysign(1.0, t.n) < 0 + elif isinstance(t.n, int): + negate = t.n < 0 + + if negate: + self.write("(- ") + val = -t.n else: - self.write(repr(t.n)) + val = t.n + + # Subsitute an overflowing decimal literal for an AST infinity + self.write(repr(t.n).replace("inf", infstr)) + + if negate: + self.write(")") + def _List(self, t): self.write("[") |